making a dataframe out of lapply() result

Dear R-helpers,

i have a question on how to vectorize this problem:

i have a dataframe:

tester <- data.frame(groups=c("A","A","B","B","C","C"), one=c(1,1,2,2,3,3), two=c(6,6,7,7,8,8))

# i split it into a list
tester.L <- split(tester, tester$groups)

# And want to keep only the first item in each:
lapply(tester.L, function(x) x <- x[1,] )


How do i make a dataframe out of the last result, which looks like
"tester", without looping? (i can use rbind in a for loop, but is
rather slow)

thanks for your help,

Remko Duursma